Concerning Gian Galeazzo's death in 1494 at Pavia, the Italian historian Francesco Guicciardini had to say in his La Historia di Italia (The History of Italy):

The rumor was widespread that Giovan Galeazzo's death had been provoked by immoderate coitus; nevertheless, it was widely believed throughout Italy that he had died not through natural illness nor as a result of incontinence, but had been poisoned ... one of the royal physicians ... asserted that he had seen manifest signs of it. Nor was there anyone who doubted that if it had been poison, it had been administered through his uncle Ludovico Sforza's machinations ...